The present invention relates to a golf club head, and more particularly relates to improvement in adjustability and ball striking characteristics of a shell type wood golf club head.
Joining a long period golf tournament, golfers usually practice subtle adjustment on condition of their golf club heads such as adjustment of lie angles and/or loft angles.
In the case of a metal club head such as an iron club head in which its hosel is formed in one body with its main body made of a metallic material, golfer's adjustment is carried out by bending the hosel with special jigs. In the case of a wood club head in which its main body is made of a wood material, golfer's adjustment is carried out by cutting the face of the main body to change its loft angle.
In the case of a shell type golf club head in which its main body is made of a fiber reinforced plastic shell (hereinafter referred to as an FRP shell), high mechanical strength and elastic nature inherent to its material does not allow easy bending of the hosel and/or easy cutting of the main body face for adjustment of conditions such as the lie angle and/or loft angle.
In construction of a conventional wood type golf club head made of wood, its main body has a one body construction. In particular, its hosel used for connection of the main body to the shaft is formed integrally of other parts on the main body such as a face, a sole, a crown and a back. Because of such an integral construction, the hosel is much vulnerable to mechanical damages to easily develop cracks therein. In order to cover this deficiency, the hosel is required to have a thick construction which naturally causes high position of the center of gravity of the club head. In the case of a conventional wood type golf club head made of metal, the relatively heavy construction of its hosel also causes high position of the center of gravity of the entire club head. When the main body is formed of an FRP shell, presence of reinforcing fibers in its hosel lowers percent void of the entire club head, thereby marring ball striking characteristics of the face on the main body. In addition, the shell construction does not allow easy deformation of the hosel for adjustment on condition of the golf club head.